Amoxicillin Dosage for 15-Month-Old with Ear Infection
For a 15-month-old baby with acute otitis media, prescribe high-dose amoxicillin at 80-90 mg/kg/day divided into 2 doses daily for 10 days. 1, 2
Dosing Algorithm Based on Clinical Presentation
Standard First-Line Treatment
- High-dose amoxicillin: 80-90 mg/kg/day in 2 divided doses is the recommended first-line therapy for this age group 3, 1, 2
- This dosing achieves middle ear fluid concentrations that exceed the minimum inhibitory concentration for intermediately resistant Streptococcus pneumoniae for a longer duration 1, 2
- Approximately 87% of S. pneumoniae isolates are susceptible to high-dose amoxicillin 1
When to Use Amoxicillin-Clavulanate Instead
Switch to high-dose amoxicillin-clavulanate (90 mg/kg/day of amoxicillin with 6.4 mg/kg/day of clavulanate in 2 divided doses) if: 1, 2
- The child received amoxicillin in the previous 30 days
- Concurrent purulent conjunctivitis is present
- Coverage for β-lactamase-producing H. influenzae or M. catarrhalis is specifically needed
Treatment Duration and Monitoring
- Treat for 10 days in children under 2 years of age 1
- Clinical improvement should be evident within 48-72 hours 1, 2
- If no improvement occurs after 48-72 hours, reassess the diagnosis and switch to amoxicillin-clavulanate or consider ceftriaxone 1, 2
Important Clinical Considerations
Why High-Dose Matters
- Research demonstrates that standard-dose amoxicillin (40 mg/kg/day) is inadequate to effectively eradicate resistant S. pneumoniae, particularly during viral coinfection 4
- High-dose therapy provides adequate middle ear fluid concentrations to cover the three most common pathogens: S. pneumoniae, H. influenzae, and M. catarrhalis 1
- The predominant pathogens in treatment failures are β-lactamase-producing organisms, which is why amoxicillin-clavulanate becomes the second-line choice 5
Practical Prescribing Details
- Twice-daily dosing is as effective as three-times-daily dosing and improves compliance 6
- If using amoxicillin-clavulanate, the 14:1 ratio formulation (amoxicillin to clavulanate) is preferred as it causes less diarrhea 1
- Always address pain management regardless of antibiotic choice 1
Common Pitfalls to Avoid
- Do not use standard-dose (40 mg/kg/day) amoxicillin in areas with drug-resistant S. pneumoniae prevalence 4, 5
- Do not prescribe amoxicillin if the child has received it in the past 30 days—use amoxicillin-clavulanate instead 1, 2
- At 15 months of age, this child falls into the 6-23 month category where antibiotics are indicated for bilateral or severe AOM, not just observation 3